Service Units Description and Operation

RHS 3000 Refrigerant Drainage And Recycling Unit - Description
This unit is used to recycle and purify R12 refrigerant from the A/C system in the car as part of service and repair work, enabling it to be reused. The RHS 3000 unit is equipped with a vacuum pump and an electronic vacuum gauge. This enables the complete recycling process, including recycling (purification), drainage, tightness testing and recharging, to be carried out without disconnecting the unit from the car. Connection between the recycling unit and A/C system is accomplished by means of hoses equipped with valves or cocks.

RHS 3000 Drainage And Recycling Unit - Principle Of Operation
Refrigerant may be recycled in gaseous or liquid form.

The refrigerant is stored in the air receiver and is evaporated passing to the compressor. Oil drawn in from the A/C system in the car is also collected in the lower section of the air receiver, in which the level can be read.

The refrigerant passes through an acid filter in the low-pressure circuit, immediately before the compressor. The suction pressure is maintained at a maximum of 2 bar (29 psi) by means of a valve. On the high-pressure side of the compressor, the refrigerant flows through an oil separator and a filter before it is condensed and fills the cylinder. Moisture is removed from the he refrigerant filters, which operate alternately, by compressed air, which itself is filtered before entering the filters. These measures eliminate the risks of moisture and acid formation.

The cylinder is equipped with a safety device which automatically prevents overfilling of the unit 4.5 kg (9.92 lb). Any non-condensable gas (air) remaining in the system is stored in the top of the cylinder, causing an increase in pressure. Under normal conditions, the cylinder pressure is 6-9 bar (87-131 psi). If the pressure rises to approx. 12 bar (174 psi), the cylinder is vented automatically.

The cylinder can be drained of refrigerant (in liquid form) through a manual shut-off valve.











RHS 650 Refrigerant Drainage And Recycling Unit - Description
Volvo has developed the RHS 650 unit to comply with the latest statutory requirements and to rationalize the handling of R134a refrigerant.

The unit is used for draining purifying and recycling the refrigerant, and can also be used to vacuum-pump test and refill the A/C system in the car.

The different settings on the unit enable it to be used on all cars using R134a.

This refrigerant may be used only in systems for which it is specified (see product plate in engine compartment). Neither may R134a be mixed with other refrigerants or used in A/C systems for which other types are specified, otherwise compressor failure may result.

The RHS 650 is designed to recover as much as possible of the refrigerant in the A/C system of the car.

The unit is supplied with one:
- oil filler syringe
- high-pressure hose (red)
- low-pressure hose (blue)
- hose for external gas bottle (yellow)
- container for recovered oil
- connection fitting for car (blue, LP)
- connection fitting for car (red, HP)
- filter drain fitting (for use when replacing filter)
- instruction manual
- quick reference guide

NOTE: Follow the instructions in the supplier's instruction manual (supplied with the unit) when replacing the filter. Filter changes should be recorded on the rear of the unit.

RHS 650 Drainage And Recycling Unit - Principle Of Operation
The unit should be connected to a single-phase, 220 V/5O grounded supply.

To endure sate, trouble-free operation:
Check the oil, filter etc. as described in the instruction manual for the unit.

Proceed as follows if there is refrigerant in the unit the evening before it is used:
Mark the refrigerant level by placing a rubber band around the gauge glass on the front of the unit. If the level has fallen or disappeared the following day, contact the maker's service personnel.








Part numbers of parts and consumable for RHS 650:
- SAE service valve for 900, complete, low-pressure, blue 9512210-7
- Hose, yellow, for external gas bottle 9512203-2
- Hose, low-pressure, blue 9512202-4
- Hose, high-pressure, red 9512201-6
- Vacuum pump oil, 0.25 liter (0.26 qt) 9511 008-6
- Oil filler syringe for RHS unit/compressor in car 9511013-5
- PAG oil for compressor in RHS 650 unit 0.25 liter (0.26 qt) 9511009-4. Required for service every 150 hours.
- Acid filter 9511012-2. Required for service every 75 hours.
- Dryer filter 9512311-3. Required for service every 75 hours.
- Copper seals (set) for dryer filter 9512312-1. Required for service every 75 hours.

Service interval(see indicator):
Every 75 hours replace acid filter and dryer filter complete with seals. Every 150 hours also change vacuum pump oil, Part Number 9511008-6. Also see instruction manual regarding 75 and 150-hourly checks.





NOTE: Fitting 9511015-1 is for 850 model cars only.

Adaptation of service valve 9512065-5 or 9511015-1 to new version.
Replace existing nipple with new nipple (8) and seal (9). Valve is now suitable for cars in which A/C system is equipped with a quick-action coupling. The 1993 model of the valve (Part Number 9512210-7) is already designed for connection to the quick-action coupling.





Refrigerant R134a. Part Number 1161390-8; 920 gramme (2.028 lb) bottle

Filler valve Part Number 9511003-7 (complete with two nipples). Suitable for RHS 850 Part Number 9511000 and RHS 650 Part Number 951 2310. Part Number 9511019-3. Nipple B (SAE) separate.

Accessory - Oil filler syringe (for compressor in car). Part Number 9512313-9. Instruction included.

Safety Precautions And Checks For RHS 650:
The following safety precautions and checks must always be carried out before using the RHS 650:

In addition: Before commencing work, read and observe SAFETY PRECAUTIONS when working on A/c systems. Technician Safety Information

WARNING:
- Mixtures of R134a and compressed air must not be used for troubleshooting due to the risk of explosion at high pressures and temperatures.

- Always wear protective goggles and gloves when working with refrigerant. Contact with eyes and skin may cause frostbite.





Check:
- oil levels in unit compressor (23) and vacuum pump (25) before starting. Top up levels as required.
- that there is no oil in the unit by opening the drain cock (18). Close cock if no oil emerges.





NOTE: Since the compressor in the car is not filed with high or low-pressure connections, only the function of the low-pressure pressostat can be checked. In this case, connection should be made as normal to the A/C system service valve.

Troubleshooting, RHS 650:
1. Carry out safety checks as described under Safety Precautions And Checks For RSH 650.
2. Connect low-pressure hose (blue) to low-pressure connection (13).
3. Connect high-pressure hose (red) to high-pressure connection (14). This hose must always be connected, even if it is not used (it may be used to fill the RHS 650 unit with refrigerant from an external gas bottle).
4. Connect unit to single-phase 220 V/SO Hz grounded supply.
5. Close valves (1), (2), (3) and (4).
6. Set selector switch (7) to TEST.





7. Connect low-pressure hose (blue) and connection fitting (21) to A/C system service valve.
8. Open valve by turning clockwise to bottom of travel (OPEN).





9. Close main switch (11).
10. Start engine and allow to idle. Switch on A/C system in car.
11. Open valve (1). Low-pressure pressostat will now operate. Low-pressure gauge (12) will indicate pressostat opening and closing pressures. For correct pressures Specifications
12. Conclude procedure as follows:
- switch off engine
- close valve (1)
- disconnect blue low-pressure hose from car
- open main switch (11).